1. Field of the Invention
This invention concerns a device for assembling printed circuit boards with an optical illuminating system for illumination of the holes in the printed circuit board into which components are to be installed.
2. Description of the Prior Art
Devices are known in which a projector is arranged at a distance above a printed circuit board to be assembled so as to be viewed by a person performing assembly operations from behind the board. Templates provided with holes are inserted into the projector. The template holes form an assembly pattern of reduced size. Rays of light penetrating through the holes are deflected downwardly by a mirror arranged directly above the printed circuit board to be assembled, so that they fall on the board. A plurality of holes may be illuminated simultaneously with such templates.
In another known device an optical system is arranged directly above the printed circuit board, but at a considerably greater distance than the mirror in the aforementioned device. This optical system is electronically controlled such that a single point of light in each instance travels to and fro between two holes to be fitted with a component.
In both systems described above the beam of light falls into the outer region of the printed circuit board, whereby larger components already mounted on the board may cut off nearby holes.
It is an object of this invention, therefore, to provide a device by which it is possible to cause beams of light serving for illumination of the holes to fall on the printed circuit board vertically or almost vertically.